The U.S. Pat. Nos. of Foote et al. 5,248,349, 5,372,646, 5,470,397 and 5,536,333, which are assigned to the assignee of the present invention and the entire disclosure of which is hereby incorporated by reference, disclose a continuous process for deposition of semiconductor material as a layer of cadmium telluride on a glass sheet substrate. The Foote et al. patents disclose source material troughs in which the cadmium telluride is received within a processing chamber that is heated. Glass sheet substrates are conveyed below the source material troughs such that sublimation of the source material from the troughs produces deposition of the semiconductor material on the upwardly facing surface of the conveyed glass sheets in a continuous manner. This construction requires that the source material troughs be periodically replenished with the cadmium telluride that provides the semiconductor material. The Foote et al. patent also disclose introduction of the source material as a vapor from sources of elemental cadmium and tellurium or from a source of cadmium telluride.